Dry concentrator



Oct. 29, 1929. J. H. MACARTNEY DRY CONCENTRATOR File uly 1928 3 Sheets-Sheet IN VEN TOR.

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0d. 29,1929. J. H. MACARTNEY 1,733,380

DRY CONCENTRATOR Fil July 1928 3 Sheets-Sheet 2 INVENTOR. J.H.MAcAR'rm-:

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Oct. 29, 1929. J. H. MACARTNEY DRY CONCENTRATOR Filed y 1928 3 Sheets-Sheet W! laid Patented Oct. 29, 19 29 UNITED STATES PATENT OFFICE JOHN H. MACARTNEY, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO AMERICAN DRY CON CENTRATOR' 00., OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF NE- VADA DRY CONCENTRATOR Application filed July 3,

This invention relates to dry concentrators and more particularly to machinery for the recovery of gold and other precious metals from soil and gangue.

At the present time in various sections of the country, large areas of gold bearing soil cannot be worked by virtue of the fact that there is an inadequate water supply and this factor has given rise to this invention. It is an object therefore of the present in vention to provide a machine for the working of gold bearing soil that will insure the recovery of a compartively large percentage of precious metal that is usually found in such soil, without the use of water.

A still further object of the invention is to provide a machine for the recovery of precious metal from soil, which, although it does not depend upon a flotation process for its operation, is highly useful and simple in its construction, convenience of arrange ment of parts and comparative inexpensive manufacture, and other desirable features that have been borne in mind in the production and development of the invention.

With these and manyother objects in view, which will more readily appear as the nature of the invention is better understood, the same consists in the novel construction, .combination and arrangement of parts, which will hereinafter be more fully described, illustrated, and claimed. Y

The essential feaures of the invention involved in the carrying out of the objects indicated are susceptible to modification; but a preferred embodiment of the invention is shown in the accompanying drawings, in which:

Fig. 1 is a top plan view of the actual concentrator table with a portion of the same broken away to more clearly reveal the nature of the invention.

Fig. 2 is a sectional view of the concentrator taken along the line 2-2 of Fig. 1, with the power operating machinery shown in elevation.

Fig. 3 is a sectional view taken along the line 3-3 of Fig. l.

Fig. 4 is a sectional view taken along the line 4-4 of Fig. 1..

1928. Serial No. 290,209.

Fig. 5 is a side elevation, partly in section of an air blast nozzle used in connection with my invention.

Fig. 6 is a front elevation of the blast nozzle shown in Fig. 5.

Fig. 7 is a side view of one of the riffles employed in connection with my invention, showing the same detached.

Fig. 8 is a sectional View taken along the line 8-8 of Fig. 7

Fig. 9 is a sectional view taken along the line 99 of Fig. 7'.

The invention will first be hereinafter more particularly described, with reference to the accompanying drawings, which are to be taken as a part of this specification, and then pointed out in the claims at the end of the description.

In the above mentioned drawings like characters of reference designate like parts throughout .and the device involves in its general organization a supporting frame 10, from which there extends uprights 11 and 12 connected together by cross members 13 and 14, which members 11, 12, 13 and 14 form the supporting structure for the driving machinery. Pivotally secured to the uprights 12 are a pair of hangers 15, which hangers support one end of the base 16 of my improved ore concentrator. This base is made up of a pair of I beams 17 connected together by cross beams 18. The .base 16 of the ore concentrator is of such dimensions as to lie in an inclined position with an end of the same lying within the sides of the base frame 10.

A pair of bifurcated supporting posts 19 are mounted centrally at opposite ends of the base 16 and within the bifurcations of each supporting post there is pivoted a bracket, which brackets are designated at 20 and 21 respectively. A bottom plate 30 extends across the machine and has its ends resting on the bracket-s 20. Supported on the bottom plate 30, centrally of the brackets 20 and 21 are a pair of transverse angle bars 22 that extend completely across the machine and have. mounted t-herebetween end plates 23 and 24. Secured along the upper edge of the end plates 23 and 2 1 are a pair of angle pieces and 26, and a second pair of angle pieces 27 and 28 are secured to the angle pieces 25 and 26 respectively. The angle pieces 25 and 27 and the angle pieces 26 and 28, have clamped therebetween the opposed edges of a flexible reciprocating partition 50. The means whereby this flexible diaphragm 50 is reciprocated, will be pointed out in detail at a later paragraph in this specification. Secured to the angle pieces 27 and 28 are a pair of end plates and 36. These end plates are connected together by side plates 37 and 38. The ore concentrator table is designated at 39 and consists of a plurality of spaced diagonally disposed rifile bars 40, to which rifiile bars is secured a fabric diaphragm 41. This diaphragm 41 extends over the upper edges of the end plates 35 and 36 and of the side plates 37 and 38 and is securely clamped thereagainst by means of a rectangular frame 42. On the upper side of the fabric diaphragm 41 overlying each lower rifiie bar 40, is an upper riftle bar 43, each upper rifile bar being secured, through the fabric diaphragm 41, to the lower riflle bar 40 by any suitable means such as the screws 44. The fabric diaphragm 41 may be constructed in any suitable manner and of any suitable material but it is preferable to form the same of laminated fabric composed of a sheet of fine wire screen 40 on which there is superimposed a layer of fine linen or other similar porous material 41. The entire diaphragm is permitted to have a slight vertical movement and toward this end the lower diagonally disposed riflie bars 40 are slidable in grooves 47 in the sides of the plates 37 and 38.

It will be seen that the end plates 35 and 36, together with the flexible portion 39, the side plates 37 and 38, and the diaphragm or ore concentrator table 41, form a closed compartment, which, except for the porosity of the fabric partition 41, is air tight. The central porous partition 50 is mounted within this compartment and is securely held against the sides of the compartment by means of a rectangular frame work 51. Likewise this partition may be formed in any suitable manner and of any suitable material but it is preferable to form the same of laminated fabric consisting in a central lamination of porous material such as canvas, hemp or burlap, on each side of which is secured a fine wire screen. The fabric forming a part of this partition is designated by the numeral 52 and the wire screens by the numerals 53 and 54. The flexible diaphragm 39 has a central check valve 55 thereon and a second check valve 56 communicates with the interior of the compartment at the upper side thereof, adjacent one corner of the concentrator table as may be clearly seen from Fig. 1,

the material forming the top of the concentrator table being cut away at this point to accommodate the check valve. The details of these check valves and their operation will become apparent as this description proceeds. It is to be noted at this point, that the upper rifile bars 43 have formed in one side thereof, tapered grooves 58. These grooves commence at one end of each riflie bar and gradually diminish in arcuate cross section and taper into obscurity adjacent the opposite end of the rifiie bar.

The above mentioned parts describe the details of construction of the actual ore concentrator proper, and I will now describe the details of construction which co-operate to reciprocate the diaphragm 29 and otherwise operate the concentrator mechanism to create an air blastwithin the compartment to agitate material placed on the concentrator table.

A pair of cross beams 60 and 61 extend transversely of the power table frame, and each of these cross beams carries a bearing. These bearings are designated respectively by the numerals 62 and 63. Pivotally mounted in these bearings 62 and 63 is a shaft-64 carrying a comparatively heavy gear wheel 68.v This gear wheel 68 has teeth 69 on the periphery thereof meshing with a small gear wheel 70 driven by any suitable source of power, such as the generator G. I find that it is preferable to construct the gear Wheel 68 of heavy material so that the same may act as a'fly wheel to overcome any eccentric thrust or any load placed on the machinery. J ournaled beneath the ore concentrator table in any suitable manner, as in bearings 71 and 72, is a shaft 7 3 and connecting rods 82 and 83 serve to connect these eccentrics to a pair of plates 84 and 85 secured to the flexible diaphragm 29. These plates 84 and 85 have depending guide rods 86 and 87 slidably mounted within brackets 88 and 89, secured to cross beams 90 and 91 on the frame of the ore concentrator table. Thus it will be seen that as the shaft 73 rotates, the eccentrics 80 and 81 impart through the medium of the connecting rods 82 and 83, a reciprocative movement of the plates 84 and 85 secured to the flexible diaphragm 29, and by virtue of the fact that the chamber is substantially. air tight, an air blast will be forced through the porous concentrator table to cause particles of ore and gangue fed thereon to be agitated and assume a state of suspension slightly above the plane of the table. The check valves 55 and 56 operate to prevent entry of air into the chamber as the diaphragm 29 moves upwardly, but permits air to enter the chamber as the diaphragm is moved downwardly.

The inclination of the concentrator table may be varied to accommodate different grades of material placed on the same. The means for varying the inclination of the table consists in a pair of threaded shafts 91, threadedly mounted on the base 16 at opposed points on either side thereof. The ends of these shafts project into brackets 92 mounted on the plate 30 and a hand wheel 93 serves as a means whereby these threaded shafts may be rotated to vary the inclination of the concentrator table.

The above mentioned parts adequately define the operative elements that co-operate to make up my improved ore concentrator table, and I will now proceed with a further description of the actual operation of the device and show the manner in which the precious metal is recovered from the finely divided ore that is placed on the table.

In actual operation, the ore is finely divided or crushed, and is fed onto the concentrator table in any suitable manner by means, not shown. As the shaft 73 is rotated and the partition is thereby caused to reciprocate, an intermittent pressure is developed within the chamber beneath the porous top of the concentrator table. This pressure is partially equalized by the central partition 50 so that a continuous blast of air is forced through the diaphragm 39 and serves to keep the lighter particles of the ore in a suspended state of agitation and suspension. The heavier particles of ore such as small nuggets, and other particles of precious metals are caught within the grooves of the rifle bars 13 and travel along the same to the end thereof where they are deposited in a chute 100, from which they are discharged at 101. In order to prevent the non-metallic lighter particles of material from entering this chute, a plurality of ore nozzles 102 are mounted along one edge of the table, each ore nozzle occupying a position adjacent a respective rifle bar 43. These air nozzles are connected to the interior of the casing by means of a by-pass 105. The nozzles are adjustable vertically and horiontally, as may be clearly seen from Fig. 4. The horiontal adjustment may be efi'ected by forming the by-pass 105 in sections that are pivoted together at 106, whereas the vertical adjustment may be effected by pivoting the nozzles 102 to the end of the upper section of the by-pass 105. Thus, it will be seen that a continuous blast of air issues from these nozzles at all times to keep the lighter particles of non-metallic material from entering the chute 100. a i

It is obvious then that 'I have provided a device which is efiicient in its operation and which does not depend upon the principle of ore flotation for the extraction of the precious metal from the ore. In actual practice I have found that a machine constructed in accordance with my invention is extremely efficient and will extract a comparatively large percentage of the precious metal from the ore.

I am aware that some changes may be made in the general arrangements and com binations of the several devices and parts, as

well as in the details of the construction thereof without departing from the scope of the present invention as set forth in the foregoing specification, and as defined in the following claims. Hence, I do not limit my invention to the exact arrangements and combinations of the said device and parts as described in the said specification, nor do I confine myself to the exact details of the construction of the said parts as illustrated in the accompanying drawings. Only in so far as I have particularly pointed out my invention in the appended claims do I desire to be limited.

In order to facilitate the cleaning of the interior of the chamber, a plug is removably mounted in an aperture 66 in the end wall 36 of the chamber. By removing this plug and operating the air blast, foreign matter that has accumulated Within the chamber will be blown out of the casing.

I claim:

1. An ore concentrator table comprised of a closed chamber having side walls, end walls, a bottom, and a concentrator table forming the top thereof, said table being formed of foraminous sheet material and having rifle bars secured thereto in spaced relationship, said rifle bars being slidable in grooves in the sides of the chamber to permit reciprocation of the table; a check valve in said bottom to admit an intermittent air blast into the interior of said chamber, a central partition in said chamber formed of foraminous material to equalize the pressure of said intermittent air blast, a trough adjacent one end of said concentrator table adapted to receive metallic particles deflected by said rifle bars; an air nozzle adjacent each rifle bar at an end thereof to prevent entry of lighter particles into said trough, each nozzle being connected by a by-pass to the interior of said casing for the purposes specified.

2. An ore concentrator table comprised of a closed chamber having side walls, end walls, a bottom, and a concentrator table forming the top thereof, said table being formed of foraminous sheet material and having rifle bars secured thereto in spaced relationship, said rifle bars being slidable in grooves in the sides of the chamber to permit reciprocation of the table, a check valve in said bottom to admit an intermittent air blast into the interior of said chamber, a central partition in said chamber formed of foraminous material to equalize the pressure of said intermittent air blast, an air nozzle adjacent each rifle bar at an end thereof to direct an air stream against the material moving downwardly over the faces of said rifle bars, each nozzle being connected to the interior of said casing whereby a pulsating air current is supplied thereto.

JOHN H. MACARTNEY. 

